California produce growers and processors worked to draw up new food-safety measures Thursday as government investigators trying to pinpoint the source of the deadly E. coli outbreak narrowed their search to three counties.

Trade groups hoped to deliver the guidelines to the Food and Drug Administration within a week but were unsure how long it would take to win the agency’s approval.

“We have people who hope this will be resolved soon so they can salvage something of this season,” said Tom Nassif, president of Western Growers Association, an industry group representing about 3,000 fruit and vegetable farmers in California and other states. “Once we go to Washington and iron out those guidelines, we’ll be much closer to a date.”

Federal officials have required the industry to adopt new food-safety measures before they will lift a week-old consumer warning on fresh spinach.

Nassif said it was too early to provide details, but that the new measures would likely focus on better water and soil testing and beefed-up sanitation standards for field workers and packaging plants.

The guidelines will be part of a proposal for protecting produce from the bacteria that have killed one person and sickened at least 157 others across the country since last month. Idaho officials were investigating the death of a 2-year-old on Wednesday, reportedly after eating spinach.

He said the industry must “declare war on all food-borne illnesses. We have to do everything to assure the American public that our food is safe to consume.”

The industry’s response to the E. coli outbreak traced to bagged spinach from central California would build on existing efforts to protect produce from contamination rather than entail a complete overhaul, Nassif said.

Bryan Silbermann, president of the Produce Marketing Association, estimated that the FDA’s Sept. 14 warning for consumers to stop eating fresh, raw spinach could cost farmers and vegetable packaging companies $50 million to $100 million a day.

Investigators found a contaminated bag of Dole baby spinach Wednesday at the New Mexico home of a person who fell ill. The spinach was packaged by Natural Selection Foods, a San Juan Bautista company that packages salad greens sold under dozens of brands.

After analyzing the strain of E. coli bacteria in the bag, investigators said they believe it probably originated in at least one of nine farms and several processing plants in California’s Monterey, San Benito or Santa Clara counties.

Bill Marler, a lawyer representing over 40 people who were sickened by E. coli, questioned whether growers and processors were doing enough to ensure the safety of their products.

“The industry is really masterful at saying, ‘We don’t know exactly how it happened, so how do we fix it?'” Marler said. “But they’ve got to get this situation dealt with so the E. coli doesn’t get on the produce in the first place.”

E. coli is often spread by human or animal waste. Inspectors have been looking at the possibility that the germ was spread by contaminated irrigation water, workers relieving themselves in the fields, or some other means.

Trade groups are seeking compensation from the state for spinach growers who saw the market for their crops disappear overnight. They also want the state to help promote crops from the Salinas Valley, which has been the center of the FDA probe to find the source of the outbreak.

Once the FDA approves the new food-safety measures, consumers are likely to find lower prices as the industry works to stimulate an appetite for spinach, Silbermann said.

“The thing that is more fragile than this product is consumer confidence, the trust that consumers have in our ability as farmers, processors, retailers and restaurant operators,” Silbermann said. “That’s what we’ve got to focus on.”